Question

I know C99 allows declarations to be mixed with code and not only at the beginning, but I’m trying to find where in ISO/IEC 9899:1999 it is written – could you point me to the section(s) I should search?

Thanks in advance.

Answer 1

The change is mentioned in the (non-normative) Forward, page xii, as “mixed declarations and code”. (IMHO, declarations are “code”; it should have said “mixed declarations and statements”.)

It’s defined in the grammar for a compound-statement in 6.8.2:

compound-statement:
    { block-item-list[opt] }
block-item-list:
    block-item
    block-item-list block-item
block-item:
    declaration
    statement

The corresponding grammar in the C89/C90 standard was:

compound-statement:
    { declaration-list[opt] statement-list[opt] }
declaration-list:
    declaration
    declaration-list declaration
statement-list:
    statement
    statement-list statement